following all the messages and polemics regarding the DP3 Merrill's colour rendition and whether it is different or not from the DP1/DP2 pair, I proceeded to a controlled test that should put this discussion to rest - I shot colour charts under controlled flash light, using different WB, computing all colorimetric values in PS, etc.

In short, the result is that there are in fact differences; especially so if you use Auto WB or WB Presets, where the DP3 is much better than the DP1/DP2, much less so if you use Custom WB in which case, actually, the DP2 and DP3 are very similar, versus the DP1 which stands alone in this case.